Method and device for the plotting of scanned information, in particular operating data for a motor vehicle

ABSTRACT

The present invention relates to a method and a device for recording the curve ( 12 ) of information. The information is scanned using a specifiable scanning period. The information is specifically the operating data of a motor vehicle. The scanned information is subjected to a data reduction, and then the reduced information is stored. To record the curve ( 12 ) of relevant digital information, in particular, of the operating data of a motor vehicle, so as to use the least possible storage space, it is proposed that, in the context of the data reduction, the curve ( 12 ) of the scanned information be viewed in a time raster of a multiple of the scanning period, and, within the individual raster increments ( 13 ), at least one characteristic variable (14, 15, 16) of the curve ( 12 ) of the scanned information be determined. The device is advantageously a component part of a control device ( 1 ) for controlling/regulating specific motor-vehicle components or of an operating- or accident-data recorder ( 2 ) of a motor vehicle.

BACKGROUND INFORMATION

[0001] The present invention relates to a method for recording the curveof information. The information is scanned using a specifiable scanningperiod. The information is specifically the operating data of a motorvehicle. Using the method, the scanned information is subjected to adata reduction. Then the reduced information is stored.

[0002] The present invention also relates to a control element for acontrol device for controlling/regulating specific motor-vehiclecomponents or for an operating- or accident-data recorder of a motorvehicle. The control element is configured, in particular, as aread-only memory (ROM), including EPROM or EEPROM, as a random-accessmemory (RAM), including FeRAM, or as a flash memory. On the controlelement, a program is stored that can be executed on a computing device,specifically on a microprocessor.

[0003] Finally, the present invention relates to a device for recordingthe curve of information. The information is scanned using a specifiablescanning period. The information is specifically the operating data of amotor vehicle. The device has a means for the data-reduction of thescanned information and a means for storing the reduced information.

[0004] The present invention also relates to a computer program and acomputer program product, in each case having a program code means, tocarry out the recording, or data reduction procedure, in accordance withthe preambles of the independent claims, when the computer program orcomputer program product is executed on a computer or a control unit.

[0005] Collecting and recording the operating data of a motor vehicle isbecoming more and more important (see also German Patent 199 14 764).The operating data are supplied by appropriate sensors and are generallymade available in digital form. The operating data can be, for example,the speed of the motor vehicle, the temperature and the operating pointof an internal combustion engine of the motor vehicle, the activation ofthe gas pedal or brakes, or the activation of specific motor-vehiclefunctions, in particular, the illumination or the directional lights.The operating data are recorded over time. Because the storage space islimited in a control device for controlling/regulating specificmotor-vehicle components or in an operating- or accident-data recorderin a motor vehicle, it is necessary to reduce the data volume to bestored.

[0006] The data volume can be reduced in different ways. First,redundancies in the information to be stored can be avoided, i.e.,identical bits of information are stored only once.

[0007] Furthermore, the data volume to be stored can be reduced througha data reduction. In this context, when being stored, information thatis not viewed as relevant is dispensed with in a controlled manner. Inthe data reduction process, the non-relevant information content isomitted in a controlled manner. The original information can bereconstructed from the reduced information but only at a loss ofinformation.

[0008] Finally, the information to be stored can be reduced by datacompression. In this context, the number of bits necessary for storingand transmitting the information is reduced. The original informationcan be reconstructed without any loss of information by decompressingthe compressed information.

[0009] While for data compression, very many different methods areknown, specifically in the area of image data compression andinformation technology (e.g., Huffmann Compression; see H. Y. P Lim,“Interactive Data Compression Tutor,” School of Electrical andElectronics Engineering, Birmingham, UK, February, 1998), as well asmethods for the reconstruction of time signals, that are based on theShannon scanning theorem (e.g., impulse train modulation; see A. V.Oppenheim, R. W. Schaefer, “Discrete-Time Signal Processing,”Prentice-Hall, Englewood Cliffs, 1989), for data reduction there existsno generally applicable method, because a loss of information is alwaysinevitable and therefore a function of the application.

[0010] From European Patent 0 834 146 B1, a method and a device areknown for the data-reduction of scanned information in an implantedmedical device. The scanned information is, for example, the heart rateof a patient. It is proposed to store the time interval between twoheart beats not as a time indication, but rather to assign to each timeindication a specific value, which requires less storage space than theactual time indication, and then to store this value.

[0011] From German Patent 41 07 198 A1, a method and a device are knownfor recording the operating data of a motor vehicle. To reduce therequirements for storage space, it is proposed to delete from the memoryinformation that is older and no longer necessary. The storage spacethat is freed up can then be used to store current information.

[0012] A method and a device of the type cited above are known, forexample, from German Patent 43 44 528 A1. In that publication, a deviceis described for storing information in the form of digital audiosignals. After a data reduction and a digital/analog (D/A) conversion,the information to be stored is saved as analog values in an analogstorage. Although this publication refers to data reduction, it isreally a matter, in this context, of data compression. As a method fordata compression, Adaptive Differential Pulse Code Modulation (ADPCM)and Linear Predictive Coding (LPC) are proposed. The stored informationcan be retrieved from the memory as audio signals via an analog/digital(A/D) inverse conversion.

[0013] The present invention is based on the objective of recording thecurve of relevant digital information, in particular, of operating dataof a motor vehicle, so as to use the least possible storage space.

[0014] To achieve this objective, on the basis of the method of the typecited above, it is proposed that, in the context of data reduction, thescanned-information curve be viewed in a time raster of a multiple ofthe scanning period, and within the individual raster increments, atleast one characteristic variable of the scanned-information curve bedetermined.

ADVANTAGES OF THE INVENTION

[0015] According to the present invention, a method is proposed forrecording information, which, in certain applications, specifically inrecording the operating data of a motor vehicle, makes possible asignificant reduction in the data volume to be recorded without a lossof relevant information content. In the method according to the presentinvention, as the relevant information content, one characteristicvariable of the scanned-information curve is stored, in each case withinone raster increment of a time raster. It is obvious that as the size ofthe raster increments increases, the data volume to be stored can bereduced by a larger factor. In addition, the fewer the characteristicvariables that are to be stored within one raster increment, the smallerthe data volume to be stored becomes.

[0016] In the method according to the present invention, information tobe recorded is reduced to the essentials, which makes possiblesignificant savings in storage space. After the data reduction processdescribed above, the data volume to be stored can be reduced evenfurther by using a supplementary data compression method.

[0017] One characteristic variable of the scanned-information curve,which can be retrieved for the method according to the presentinvention, is, for example, a turning point in the curve of the scannedvalues, the variance or the standard deviation of the scanned values, ineach case within one single raster increment. However, according to oneadvantageous refinement of the present invention, it is suggested thatthe maximum values and/or minimum values of the scanned values withinthe raster increments be determined as the characteristic variable ofthe scanned-information curve. Within one raster increment, thescanned-information curve is therefore represented by envelopescorresponding to the maximum value and/or the minimum value of thescanned values.

[0018] Alternatively or additionally, it is proposed that the averagevalue of the scanned values within the raster increments be determinedas the characteristic variable of the scanned-information curve. On thebasis of the deviation of the envelope curve, a specific degree of datareduction can be read directly from the average value curve. In theevent that the curves are situated far apart from each other, the curvewithin the raster increment in question has varied substantially. If thecurves are situated close to each other, the curve has remained at avirtually constant value.

[0019] According to one preferred embodiment of the present invention,it is proposed that the raster increments be selected so as to beidentical in size.

[0020] According to one alternative embodiment of the present invention,it is proposed that the raster increments be selected so as to vary as afunction of further characteristic variables of the scanned-informationcurve within one raster increment. The size of the raster increments istherefore coupled to specific signal characteristics, which aredescribed on the basis of the characteristic variables. Examples ofthese signal characteristics are statistical variables. The rasterincrements are advantageously selected so as to vary as a function ofthe standard deviation of the scanned values of the information curvewithin one raster increment. The raster increments are advantageouslyselected so as to be so small that the standard deviation does notexceed a specifiable value.

[0021] Furthermore, it is proposed that the raster increments beselected so as to vary as a function of the distance from the maximumvalue or from the minimum value to an average value of the scannedvalues within one raster increment of the information curve.Advantageously, the raster increments are selected so as to be so smallthat the distance does not exceed a specifiable value.

[0022] Of special significance is the realization of the methodaccording to the present invention in the form of a control element thatis provided for a control device for controlling/regulating specificmotor-vehicle components or for an operating- or accident-data recorderof a motor vehicle. Stored on the control element in this context is aprogram that can be executed on a computing device, in particular, on amicroprocessor, and that is well suited for carrying out the methodaccording to the present invention. In this case, the present inventionis therefore realized by a program that is stored on the controlelement, so that this control element, which is furnished with theprogram, represents the present invention in the same way as does themethod that the program is designed to carry out. The control elementcan be, in particular, an electrical storage medium, for example, aread-only memory, a random-access memory, or a flash memory.

[0023] Proceeding on the basis of the device for recording thescanned-information curve of the type cited above, as a further solutionof the objective of the present invention, it is proposed that the meansfor data reduction view the scanned-information curve in a time rasterof a multiple of the scanning period, and determine, within the specificraster increments, at least one characteristic variable of thescanned-information curve.

[0024] According to one advantageous refinement of the presentinvention, it is proposed that the device have a means for carrying outthe method according to the present invention.

[0025] According to a preferred embodiment of the present invention, itis proposed that the device be a component part of at least one controldevice for controlling/regulating specific motor-vehicle components.

[0026] Alternatively, it is proposed that the device be a component partof an operating- or accident-data recorder of a motor vehicle.

[0027] In general, with regard to the examples of the motor-vehiclecontrol device, the operating-data recorder, as well as theaccident-data recorder, the method according to the present inventioncan be carried out on a, or by a, computer or control unit. Therefore,the device according to the present invention can generally be viewed asa component part of a computer, or of a control unit.

[0028] In this context, steps of the method according to the presentinvention, or the method according to the present invention itself, isalso carried out, if an appropriate computer program or an appropriatecomputer program product on a data carrier, in each case having programcode means, is executed on a computer or a control unit. In thiscontext, specifically in addition to a fixedly installed control elementcited above, the data carrier can also be a mobile data carrier such asa CD-ROM, DVD, diskette, or any other optical, magnetic,electromagnetic, etc., storage medium, if the data carrier is, or ismade, readable by a computer using appropriate auxiliary means.

[0029] Further advantages and advantageous embodiments can be derivedfrom the claims.

DRAWINGS

[0030] Further features, application possibilities, and advantages ofthe present invention can be seen in the following description ofexemplary embodiments of the present invention, which are depicted inthe drawing. In this context, all of the described or depicted features,by themselves or in any combination, constitute the subject matter ofthe present invention, irrespective of their summary in the patentclaims or their antecedent reference, as well as irrespective of theirformulation in the description or depiction in the drawing. In thiscontext, as was already mentioned, the preferred examples, themotor-vehicle control device and the operating- or accident-datarecorder, can generally be expanded to a computer or control unit, usingthe appropriate device or the appropriate control element. Therefore,steps of the method according to the present invention, or the method ofthe present invention itself, is carried out if an appropriate computerprogram or an appropriate computer program product on a data carrier isexecuted on the computer or on the control unit. The following are thecontents:

[0031]FIG. 1 depicts a device according to the present invention inaccordance with a first preferred embodiment of the present invention;

[0032]FIG. 2 depicts a device according to the present invention inaccordance with a second preferred embodiment of the present invention;

[0033]FIG. 3 depicts a flow diagram of the method according to thepresent invention in accordance with one preferred embodiment; and

[0034]FIG. 4 depicts a curve of information to be recorded.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0035] The method according to the present invention functions to recordthe curve of information. The information to be recorded is specificallythe operating data of a motor vehicle. The operating data are suppliedby appropriate sensors and are made available in digital form, i.e., thecontinuous temporal curve of the operating data signal is scanned usinga specifiable scanning period. The operating data to be recorded are,for example, the speed of the motor vehicle, the temperature and theoperating point of the internal combustion engine of the motor vehicle,the actuation of the gas pedal or brakes, or the actuation of specificmotor-vehicle functions, specifically the illumination or thedirectional lights.

[0036] The method according to the present invention is carried out in acontrol device 1 for controlling/regulating specific motor-vehiclecomponents (see FIG. 1) or in an operating- or accident-data recorder 2(see FIG. 2) of a motor vehicle. In control device 1, a control element3 is provided, on which a program is stored that can be executed on amicroprocessor 4. As control element 3, it is possible to use, inparticular, an electrical storage medium, for example, a read-onlymemory, a random-access memory, or a flash memory. The program functionsfor the control/regulation of the motor-vehicle components. For thispurpose, control device 1 is acted upon by input signals 5, which, usingsensors, represent measured operating variables of an internalcombustion engine or of other components of the motor vehicle. Controldevice 1 generates output signals 6, which, via actuators, orcontrollers, can influence the behavior of specific motor-vehiclecomponents.

[0037] On control element 3 of control device 1 from FIG. 1, a furtherprogram is stored, which can be executed on microprocessor 4 and whichis well suited for carrying out the method according to the presentinvention. The operating data to be recorded are stored in a furtherstorage element 7 of control device 1.

[0038] In the exemplary embodiment from FIG. 2, operating- oraccident-data recorder 2 has a control element 8 and a microprocessor 9.Stored on control element 8 is a further program that can be executed onmicroprocessor 9 and that is suited for carrying out the methodaccording to the present invention. As element 8, it is possible to use,in particular, an electric storage medium, for example, a read-onlymemory (ROM), including EPROM or EEPROM, a random-access memory (RAM),including FeRAM, or a flash memory. The operating data to be recordedare stored in a further storage element 10 of operating- oraccident-data recorder 2. Information to be recorded is transmitted fromcontrol device 1 to operating- or accident-data recorder 2 via asuitable data interface 11.

[0039] Because the storage space is limited in a control device, or inan operating- or accident-data recorder, it is necessary to reduce thedata volume to be stored. Therefore, the scanned operating data arefirst subjected to a data reduction. Thereupon, the reduced operatingdata either, for a further reduction of the data volume, can besubjected to a data compression and only then stored in further storageelement 7 or 10, or they can be stored immediately.

[0040]FIG. 3 depicts a flow diagram of a method according to the presentinvention for recording the operating data of a motor vehicle. Thetemporal curve of the operating data to be recorded is designated inFIG. 4 as reference numeral 12. The method begins in function block 20.Then in a function block 21, in the context of the data reduction,raster increments 13 are determined of a time raster in which curve 12of the operating data to be recorded is viewed. Raster increments 13 area multiple of the scanning period, in the present case, 400×10⁻⁶seconds.

[0041] In a function block 22, within individual raster increments 13, aplurality of characteristic variables of curve 12 of the scannedoperating data are determined. In a function block 23, the measuredcharacteristic variables are then stored in further storage element 7,10. According to the present invention, not some or all scanning valuesof curve 12 of the operating data to be recorded are stored, but ratheronly the characteristic variables within raster increments 13.

[0042] The data reduction underlying the method according to the presentinvention is discussed in greater detail on the basis of FIG. 4. In thepresent exemplary embodiment, as characteristic variables, maximum value14, minimum value 15, and average value 16 of the scanning values ofcurve 12 are determined within one raster increment 13. Nevertheless, itis also possible to measure any other characteristic variable. Rasterincrements 13 can either be selected so as to be identical in size or soas to vary as a function of further characteristic variables of curve 12of the scanned operating data. As further characteristic variables, onecan mention, for example, statistical variables of the scanned values ofcurve 12, in particular, the standard deviation, within one rasterincrement 13. In this context, raster increments 13 can be selected soas to be so small that the standard deviation does not exceed aspecifiable value.

[0043] Alternatively, raster increments 13 are selected so as to vary asa function of the distance from maximum value 14 or from minimum value15 to average value 16 of the scanned values of curve 12 within oneraster increment 13. In this context, raster increments 13 are selectedso as to be so small that the distance does not exceed a specifiablevalue.

What is claimed is:
 1. A method for recording the curve (12) ofinformation scanned using a specifiable scanning period, especially ofthe operating data of a motor vehicle, in which the scanned informationis subjected to a data reduction and the reduced data are stored,wherein, in the context of the data reduction, the curve (12) of thescanned information is viewed in a time raster of a multiple of thescanning period, and, within the individual raster increments (13), atleast one characteristic variable (14, 15, 16) of the curve (12) of thescanned information is determined.
 2. The method as recited in claim 1,wherein, as a characteristic variable of the curve (12) of the scannedinformation, the maximum values (14) and/or the minimum values (15) ofthe scanned values within the raster increments (13) are determined. 3.The method as recited in claim 1 or 2, wherein, as a characteristicvariable of the curve (12) of the scanned information, the average value(16) of the scanned values within the raster increments (13) isdetermined.
 4. The method as recited in one of claims 1 through 3,wherein the raster increments (13) are selected so as to be identical insize.
 5. The method as recited in one of claims 1 through 3, wherein theraster increments (13) are selected so as to vary as a function offurther characteristic variables of the curve (12) of the scannedinformation within one raster increment (13).
 6. The method as recitedin claim 5, wherein the raster increments (13) are selected so as tovary as a function of the standard deviation of the scanned values ofthe curve (12) of the information within one raster increment (13). 7.The method as recited in claim 6, wherein the raster increments (2) areselected so as to be so small that the standard deviation does notexceed a specifiable value.
 8. The method as recited in claim 5, whereinthe raster increments (13) are selected so as to vary as a function ofthe distance of the maximum value (14) or of the minimum value (15) fromthe average value (16) of the scanned values within one raster increment(13) of the curve (12) of the information.
 9. The method as recited inclaim 8, wherein the raster increments (13) are selected so as to be sosmall that the distance does not exceed a specifiable value.
 10. Acontrol element (3, 8), in particular, a read-only memory (ROM),including an EPROM or an EEPROM, a random-access memory (RAM), includinga FeRAM, or a flash memory, for a control device (1) forcontrolling/regulating certain motor-vehicle components or for anoperating recorder or accident-data recorder (2) of a motor vehicle, onwhich a program is stored, which can be executed on a computing device,in particular on a microprocessor (4, 9), and which is suited forcarrying out a method as recited in one of claims 1 through
 9. 11. Adevice for recording the curve (12) of information scanned using aspecifiable scanning period, in particular, of the operating data of amotor vehicle, the device having means for the data reduction of thescanned information and means for storing the reduced data, wherein themeans for the data reduction views the curve (12) of the scannedinformation in a time raster of a multiple of the scanning period, and,within the individual raster increments (13), determines at least onecharacteristic variable of the curve (12) of the scanned information.12. The device as recited in claim 11, wherein the device has means forcarrying out the method as recited in one of claims 1 through
 9. 13. Thedevice as recited in claim 11 or 12, wherein the device is a componentpart of at least one control device (1) for controlling/regulatingcertain motor-vehicle components.
 14. The device as recited in claim 11or 12, wherein the device is a component part of an operating data oraccident data recorder (2) of a motor vehicle.
 15. A computer programhaving program code means, to carry out all the steps of at least one ofclaims 1 through 9, if the computer program is executed on a computer.16. A computer program product having program code means, which arestored on a data carrier that can be read by a computer, to carry outthe method as recited in at least one of claims 1 through 9, if thecomputer program product is executed on a computer.